The Pentagon, concerned about the danger that small, armed drones pose to US troops, is moving forward with a project that looks beyond remote-control aircraft used by the Islamic State to an even more complex problem: an aerial raid of autonomous suicide bombers.
The unmanned bombers have not yet appeared in combat, but defense officials already are researching how to stop them. Laden with explosives or other dangerous materials, they would operate by crashing into US troops in a combat zone and would not be as easy to detect as existing drones used by the Islamic State, because they would not rely on radio frequencies for remote controlling. Instead, they would be programmed to carry out a specific mission, making them especially hard to see coming.
The effort to stop the aircraft is known as the Mobile Force Protection Program and is overseen by the Defense Advanced Research Projects Agency, which examines ways that technology can help the US military. DARPA anticipates awarding contracts within weeks for the first of three phases of testing and research, said J.C. Ledé, who oversees the program.
‘‘Right now, the best way of detecting that there is an unmanned airplane is by listening for that radio signal,’’ Ledé said. ‘‘Once they stop emitting that radio signal, they’re going to get a lot harder to find.’’
Early stages of the research were launched in October with a solicitation to industry, and final proposals for the first phase are due in January, according to DARPA documents. The program is focused specifically on going beyond using electronic jamming to stop unmanned planes and helicopters of to 200 pounds. Each company picked is expected to get about $3 million in the first phase, with the possibility of continuing on to two subsequent phases of work that are longer and more lucrative.
Ledé said he and his team focused on defending a convoy with important cargo aboard, because it is more complicated than defending a stationary target and because what is learned will apply in other circumstances. Unmanned aircraft are now ‘‘sufficiently inexpensive’’ that the US military must anticipate some of them may be flown directly into US troops or vehicles as part of an attack, he said.
‘‘If you are going to attack a high-value convoy, I think they would be willing to commit the hardware to it,’’ he said. ‘‘At most, it’s a few thousand dollars worth of hardware for a UAV.’’
The effort comes as the US military more broadly examines an array of ways to take out potential enemy drones. Marine Lieutenant Colonel Dave Sousa, who examines the problem for his service, said shotguns, sniper rifles, water cannons, mini-rockets, and lasers all have been considered, and the services increasingly are working together on the problem.
‘‘When you’re more than a couple hundred meters out, you can’t tell what that thing is carrying,’’ Sousa said of unmanned aircraft. ‘‘You can’t tell if it has a GoPro camera. . . . You don’t know what it is. So you’ve got to detect, track and ID, and then there’s how you’re going to deal with that threat.’’
In Iraq and Syria, Islamic State militants have loaded grenades on small drones and used them to attack civilians and local forces working to drive them out. In Ukraine, pro-Russian separatists and Ukrainian soldiers have used small unmanned aircraft to find and track opposing forces. The United States sent Ukraine some mini-drones last year, but Russian-backed separatists were able to easily jam them, rendering them relatively useless, according to a Reuters report.